Does Internet Explorer 9 support the "form" attribute of the button tag? In particular, clicking the button in the following example submits the form in Firefox and Chrome, but does nothing in IE 9:
<form id="myform" action="/action" method="POST">
<input type='hidden' name='foo' value='bar' />
</form>
<!-- Other content here, irrelevant for this example -->
<button form="myform">Click me</button>